diff --git a/libhttp/http.h b/libhttp/http.h
index 9bd2bf6..f1119eb 100644
--- a/libhttp/http.h
+++ b/libhttp/http.h
@@ -56,6 +56,8 @@
 #define HTTP_SUSPEND       3
 #define HTTP_PARTIAL_REPLY 4
 
+#define NO_MSG             "\001"
+
 #define NOINTR(x) ({ int i__; while ((i__ = (x)) < 0 && errno == EINTR); i__;})
 
 typedef struct HashMap HashMap;
diff --git a/libhttp/httpconnection.c b/libhttp/httpconnection.c
index 7a6f619..af1ee03 100644
--- a/libhttp/httpconnection.c
+++ b/libhttp/httpconnection.c
@@ -63,8 +63,6 @@
 #define MAX_HEADER_LENGTH   (64<<10)
 #define CONNECTION_TIMEOUT  (10*60)
 
-static const char *NO_MSG;
-
 static int httpPromoteToSSL(struct HttpConnection *http, const char *buf,
                             int len) {
   if (http->ssl->enabled && !http->sslHndl) {
@@ -1253,7 +1251,7 @@ void httpSendReply(struct HttpConnection *http, int code,
   char *body;
   char *title    = code != 200 ? stringPrintf(NULL, "%d %s", code, msg) : NULL;
   char *details  = NULL;
-  if (fmt != NULL) {
+  if (fmt != NULL && strcmp(fmt, NO_MSG)) {
     va_list ap;
     va_start(ap, fmt);
     details      = vStringPrintf(NULL, fmt, ap);
@@ -1274,7 +1272,7 @@ void httpSendReply(struct HttpConnection *http, int code,
      "%s\n"
      "</body>\n"
      "</html>\n",
-     title ? title : msg, fmt ? details : msg);
+     title ? title : msg, fmt && strcmp(fmt, NO_MSG) ? details : msg);
   free(details);
   free(title);
   char *response = NULL;
diff --git a/libhttp/httpconnection.h b/libhttp/httpconnection.h
index dfe210c..2c1e9cd 100644
--- a/libhttp/httpconnection.h
+++ b/libhttp/httpconnection.h
@@ -60,6 +60,8 @@
 #define HTTP_SUSPEND       3
 #define HTTP_PARTIAL_REPLY 4
 
+#define NO_MSG             "\001"
+
 struct HttpConnection {
   struct Server           *server;
   struct ServerConnection *connection;
diff --git a/libhttp/server.c b/libhttp/server.c
index 0ae92b2..92de1b3 100644
--- a/libhttp/server.c
+++ b/libhttp/server.c
@@ -68,8 +68,6 @@
 // API should be used, instead.
 #define MAX_PAYLOAD_LENGTH (64<<10)
 
-static const char *NO_MSG;
-
 time_t currentTime;
 
 struct PayLoad {
diff --git a/libhttp/ssl.c b/libhttp/ssl.c
index af01bff..f098e47 100644
--- a/libhttp/ssl.c
+++ b/libhttp/ssl.c
@@ -335,8 +335,9 @@ static int sslSNICallback(SSL *sslHndl, int *al, struct SSLSupport *ssl) {
   if (context == NULL) {
     check(context         = SSL_CTX_new(SSLv23_server_method()));
     check(ssl->sniCertificatePattern);
-    char *certificate     = stringPrintf(NULL, ssl->sniCertificatePattern,
-                                         serverName);
+    char *certificate     = stringPrintfUnchecked(NULL,
+                                                  ssl->sniCertificatePattern,
+                                                  serverName);
     if (!SSL_CTX_use_certificate_file(context, certificate, SSL_FILETYPE_PEM)||
         !SSL_CTX_use_PrivateKey_file(context, certificate, SSL_FILETYPE_PEM) ||
         !SSL_CTX_check_private_key(context)) {
diff --git a/logging/logging.c b/logging/logging.c
index a386fd0..555464d 100644
--- a/logging/logging.c
+++ b/logging/logging.c
@@ -178,3 +178,6 @@ char *stringPrintf(char *buf, const char *fmt, ...) {
   va_end(ap);
   return s;
 }
+
+char *stringPrintfUnchecked(char *buf, const char *fmt, ...)
+  __attribute__((alias("stringPrintf")));
diff --git a/logging/logging.h b/logging/logging.h
index 28d8f76..b96d856 100644
--- a/logging/logging.h
+++ b/logging/logging.h
@@ -89,5 +89,6 @@ void logSetLogLevel(int level);
 char *vStringPrintf(char *buf, const char *fmt, va_list ap);
 char *stringPrintf(char *buf, const char *fmt, ...)
   __attribute__((format(printf, 2, 3)));
+char *stringPrintfUnchecked(char *buf, const char *fmt, ...);
 
 #endif /* LOGGING_H__ */
diff --git a/shellinabox/externalfile.c b/shellinabox/externalfile.c
index b7548c9..f16287c 100644
--- a/shellinabox/externalfile.c
+++ b/shellinabox/externalfile.c
@@ -59,8 +59,6 @@
 #include "libhttp/server.h"
 #include "logging/logging.h"
 
-static const char *NO_MSG;
-
 static int externalFileHttpHandler(HttpConnection *http, void *arg,
                                    const char *buf, int len) {
   checkGraveyard();
diff --git a/shellinabox/shellinaboxd.c b/shellinabox/shellinaboxd.c
index 3186709..18ac50f 100644
--- a/shellinabox/shellinaboxd.c
+++ b/shellinabox/shellinaboxd.c
@@ -52,6 +52,7 @@
 #include <limits.h>
 #include <locale.h>
 #include <poll.h>
+#include <stdarg.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
@@ -75,8 +76,6 @@
 #define PORTNUM           4200
 #define MAX_RESPONSE      2048
 
-static const char *NO_MSG;
-
 static int     port;
 static int     portMin;
 static int     portMax;
@@ -155,6 +154,18 @@ static char *jsonEscape(const char *buf, int len) {
   return result;
 }
 
+static int printfUnchecked(const char *format, ...) {
+  // Some Linux distributions enable -Wformat=2 by default. This is a
+  // very unfortunate decision, as that option generates a lot of false
+  // positives. We try to work around the problem by defining an unchecked
+  // version of "printf()"
+  va_list ap;
+  va_start(ap, format);
+  int rc = vprintf(format, ap);
+  va_end(ap);
+  return rc;
+}
+
 static int completePendingRequest(struct Session *session,
                                   const char *buf, int len, int maxLength) {
   // If there is no pending HTTP request, save the data and return
@@ -970,7 +981,7 @@ int main(int argc, char * const argv[]) {
            "X-ShellInABox-Pid: %d\r\n"
            "Content-type: text/html; charset=utf-8\r\n\r\n",
            port, pid);
-    printf(cgiRoot, port, cgiSessionKey);
+    printfUnchecked(cgiRoot, port, cgiSessionKey);
     fflush(stdout);
     free(cgiRoot);
     check(!NOINTR(close(fds[1])));